Asymmetric dendrimers

Abstract

Asymmetric light-emitting dendrimers having the formulae: (a) CORE-[DENDRITE1]n[DENDRITE2]m and (b) CORE-[DENDRITE]n are disclosed.

1. A light emitting dendrimer having the formula:
   CORE-[DENDRITE 1 ] n [DENDRITE 2 ] m    
 in which CORE represents an atom or group, n and m, which may be the same or different, each represent an integer of at least 1, each DENDRITE 1 , which may be the same or different when n is greater than 1, and each DENDRITE 2 , which may be the same or different when no is greater than 1, represent dendritic structures, at least one of said structures being fully conjugated and comprising aryl and/or heteroaryl groups and, optionally, vinyl and/or acetylenyl groups, connected via sp 2  or sp hybridized carbon atoms of said aryl, heteroaryl, vinyl and acetylenyl groups, and at least one branching point and/or link between branching points in DENDRITE 1  being different from those in DENDRITE 2 , CORE terminating in the single bond which is connected to a sp 2  hybridized (ring) carbon atom of the first (hetero)aryl group to which more than one conjugated dendritic branch is attached, said ring carbon atom forming part of said fully conjugated DENDRITE 1  or DENDRITE 2  and CORE terminating at the single bond to the first branching point for the other of said DENDRITE 1  or DENDRITE 2 , at least one of the CORE, DENDRITE 1  and DENDRITE 2  being luminescent, wherein the dendrimer is luminescent in the solid state. 
 
     
     
       2. A dendrimer according to  claim 1 , wherein the CORE is luminescent. 
     
     
       3. A dendrimer according to  claim 1 , wherein at least one component of the dendritic structures is luminescent. 
     
     
       4. A dendrimer according to  claim 1 , wherein the HOMO-LUMO energy gap of the CORE is lower than that of the conjugated moieties in the dendritic structures. 
     
     
       5. A dendrimer according to  claim 1 , wherein the HOMO-LUMO energy gap of the moieties in the dendritic structures generally decreases from the surface to the point of attachment to the core. 
     
     
       6. A light emitting device comprising a layer of a dendrimer according to  claim 1 . 
     
     
       7. A light emitting device according to  claim 6 , further comprising at least one of a hole-transporting layer and an electron-transporting layer. 
     
     
       8. A light emitting device according to  claim 6 , wherein the layer comprising the dendrimer further includes another material. 
     
     
       9. A light emitting device according to  claim 8 , wherein said material is an organic material. 
     
     
       10. A light emitting device according to  claim 6 , which is a light emitting diode (LED). 
     
     
       11. A dendrimer according to  claim 1 , wherein DENDRITE 1  comprises a branching point between branching points which is different from those in DENDRITE 2 . 
     
     
       12. A dendrimer according to  claim 1 , wherein DENDRITE 1  comprises a link between branching points which is different from those in DENDRITE 2 . 
     
     
       13. A light emitting dendrimer having the formula:
   CORE-[DENDRITE] n    
 
       in which CORE represents an atom or group, n represents an integer of at least 1, each DENDRITE, which may be the same or different, represents an inherently at least partially conjugated dendritic molecular structure which comprises aryl and/or heteroaryl and, optionally, vinyl and/or acetylenyl groups, connected via sp 2  or sp hybridized carbon atoms of said aryl, heteroaryl, vinyl and acetylenyl groups, and wherein the links between at least one pair of adjacent branching points in said DENDRITE are different such that if two links are to be regarded as different then one said link must comprise at least one aryl, heteroaryl, vinyl or acetylenyl group which is not present in the other of said two links, CORE terminating in the single bond which is connected to a sp 2  hybridized (ring) carbon atom of the first (hetero)aryl group to which more than one dendritic branch is attached, said ring carbon atom forming part of said DENDRITE, at least one of the CORE and the DENDRITE being luminescent, wherein the dendrimer is luminescent in the solid state. 
     
     
       14. A dendrimer according to  claim 13 , wherein the CORE is luminescent. 
     
     
       15. A dendrimer according to  claim 13 , wherein at least one component of the dendritic structures is luminescent. 
     
     
       16. A dendrimer according to  claim 13 , wherein the HOMO-LUMO energy gap of the CORE is lower than that of the conjugated moieties in the dendritic structures. 
     
     
       17. A dendrimer according to  claim 13 , wherein the HOMO-LUMO energy gap of the moieties in the dendritic structures generally decreases from the surface to the point of attachment to the core. 
     
     
       18. A light emitting device comprising a layer of a dendrimer according to  claim 13 . 
     
     
       19. A light emitting device according to  claim 18 , further comprising at least one of a hole-transporting layer and an electron-transporting layer. 
     
     
       20. A light emitting device according to  claim 18 , wherein the layer comprising the dendrimer further includes another material. 
     
     
       21. A light emitting device according to  claim 20 , wherein said material is an organic material. 
     
     
       22. A light emitting device according to  claim 18 , which is a light emitting diode (LED).